Lidar, mentioned in the article, has also been used in Central America: <a href="http://www.caracol.org/include/files/chase/CCW2013.pdf" rel="nofollow">http://www.caracol.org/include/files/chase/CCW2013.pdf</a><p>It's a really clever, very simple technique: by taking the furthest return, you can see through gaps in the forest canopy to get a high-resolution map of surface topography beneath it.